Answer:
What forms of energy does a burning candle give out?
- The burning candle is converting chemical energy—stored in the hydrocarbon bonds in the wax—into thermal (heat) and radiant (light) energy.
What questions do you have about energy?
- Can momentum be hidden to human eyes like how kinetic energy can be hidden as heat?
- Can you go fast enough to get enough mass to become a black hole?
- How can a material at a certain temperature have all of its molecules at the same energy?
- How can we travel to the past?
You need to use the % information to determine the empirical formula of the compound first.
The empirical formula is the simplest ratio of atoms in the molecule.
Then use the rest of the data to determine moles of gas, and use this to determine molar mass of gas...
Empirical formula calculations:
Assume you have 100 g, calculate the moles of each atom in the 100 g
moles = mass / molar mass
molar mass C = 12.01 g/mol
molar mass H = 1.008 g/mol
molar mass O = 16.00 g/mol
C = 64.9 % = 64.6 g
H = 13.5 % = 13.5 g
O = 21.6 % = 21.6 g
moles C = 64.6 g / 12.01 g/mol = 5.38 mol
moles H = 13.5 g / 1.008 g/mol = 13.39 mol
moles O = 21.6 g / 16.00 g/mol = 1.35 mol
So ratio of C : H : O
is 5.38 mol : 13.39 mol : 1.35 mol
Divide each number in the ratio by the lowest number to get the simplest whole number ratio
(5.38 / 1.35) : (13.39 / 1.35) : (1.35 / 1.35)
4 : 10 : 1
empirical formula is
C4H10O
Finding moles and molar mass calcs
Now, you know that at 120 deg C and 750 mmHg that 1.00L compound weighs 2.30 g.
We can use this information to determine the molar mass of the gas after first working out how many moles the are in the 1.00 L
PV = nRT
P = pressure = 750 mmHg
V = volume = 1.00 L
n = moles (unknown)
T = temp in Kelvin (120 deg C = (273.15 + 120) Kelvin)
- T = 393.15 Kelvin
R = gas constant, which is 62.363 mmHg L K^-1 mol^-1 (when your P is in mmHg and volume is in L)
n = PV / RT
n = (750 mmHg x 1.00 L) / (62.363mmHg L K^-1 mol^-1 x 393.15 K)
n = 0.03059 moles of gas
We know moles = 0.03509 and mass = 2.30 g
So we can work out molar mass of the gas
moles = mass / molar mass
Therefore molar mass = mass / moles
molar mass = 2.30 g / 0.03059 mol
= 75.19 g/mol
Determine molecular formula
So empirical formula is C4H10O
molar mass = 75.19 g/mol
To find the molecular formula you divide the molar mass by the formula weight of the empirical formula...
This tells you how many times the empirical formula fits into the molecular formula. Tou then multiply every atom in the empirical formula by this number
formula weight C4H10O = 74.12 g/mol
Divide molar mass by formula weight empirical
75.15 g/mol / 74.12 g/mol
= 1
(It doesn't matter that the number don't quite match, they rarely do in this type of calc (although I could have made a slight error somewhere) but the numbers are very close, so we can say 1.)
The empirical formula only fits into the molar mass once,
molecular formula thus = empirical formula
<span>
C4H10O
Therefore, the </span>molecular formula of the compound is <span>C4H10O.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!</span>
Pls complete your question
39.25 g of water (H₂O)
Explanation:
We have the following chemical reaction:
2 H₂ + O₂ → 2 H₂O
Now we calculate the number of moles of each reactant:
number of moles = mass / molar weight
number of moles of H₂ = 14.8 / 2 = 7.4 moles
number of moles of O₂ = 34.8 / 32 = 1.09 moles
We see from the chemical reaction that 2 moles of H₂ will react with 1 mole of O₂ so 7.4 moles of H₂ will react with 3.7 moles of O₂ but we only have 1.09 moles of O₂ available. The O₂ will be the limiting reactant. Knowing this we devise the following reasoning:
if 1 moles of O₂ produces 2 moles of H₂O
then 1.09 moles of O₂ produces X moles of H₂O
X = (1.09 × 2) / 1 = 2.18 moles of H₂O
mass = number of moles × molar weight
mass of H₂O = 2.18 × 18 = 39.25 g
Learn more about:
limiting reactant
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